And options are running out in the number two shirt, especially if former England hooker Mark Regan is banned by Rugby Football Union disciplinary chiefs on Monday.
Regan faces a hearing in London after being cited for allegedly kicking an opponent during Bristol's victory over Premiership title rivals Gloucester nine days ago.
Any period of suspension would see Regan joining David Blaney (rib cartilage) and Neil Clark (knee) on the sidelines, leaving Saul Nelson as the club's only recognised hooking specialist.
Blaney was hurt during a 34-3 EDF Energy Cup defeat against the Ospreys and is unlikely to be available again until early January, while Clark's long-term absence potentially sees Bristol head coach Richard Hill with few options.
Hill said: "It looks like we have lost David for about a month.
"If we lose Mark Regan after his disciplinary hearing, then it would be Saul Nelson starting next week and (prop) Alex Clarke providing hooking cover."
A second-string Bristol outfit - only scrum-half Brian O'Riordan remained from the Gloucester game - were swept away by three Ospreys tries in 10 minutes during the second-half, with 21-year-old Wales centre prospect James Hook's brilliant solo score proving the highlight.
"There is a lot more to come from us, we can all see that," said Ospreys boss Lyn Jones, whose team joined Cardiff Blues, Sale and Leicester in this season's Anglo-Welsh semi-finals.